- R.G. Kachanoski, R. Rudra, and E. Pringle, University of Guelph, Guelph,
Evaluation Summary (Tech. Transfer Report Summaries)
View / Download Report [1378 KB pdf]
Associated SWEEP/LSP Research
Completed: January, 1992
water quality, tillage, surface drainage, subsurface drainage, surface
runoff, tile drainage, no-till, moldboard plow, nitrate nitrogen, phosphorus,
macropore transport, leaching
A study was undertaken to determine the effects of tillage system on
the quantity and quality of surface runoff and tile drainage water. Previous
studies have suggested that the increased infiltration and occurrence of
macropores in no-till systems may increase the risk of movement of chemicals
to the groundwater. Thus, no-till systems may solve one problem (surface
water quality), but create another problem (groundwater quality).
The study was carried out on the long term no-till - moldboard plough
comparison established by Don Lobb, a conservation farmer near Clinton,
Ontario. The soil at the site is a sandy loam. Three tile lines in each
of the two tillage systems were instrumented for monitoring tile flow quantity
and the concentrations of nitrate nitrogen and phosphorus.
Multi-level groundwater samplers were also installed in each treatment,
and soil coring and the application of tracers (chloride) were used to track
the movement of soluble chemicals. Detailed solute transport experiments
under controlled application of water were also carried out to characterize
the soil transport properties. The installation of equipment was started
in the fall of 1988 and finished in spring of 1989. The site was planted
with corn in 1989 and soybeans in 1990.
Surface runoff was monitored by installing runoff collection flumes on
selected soil landscape positions within the study field. Rainfall simulation
studies and characterizations of the hydraulic soil properties controlling
surface runoff were also carried out in cooperation with other studies.
No significant tile flow was recorded until late fall 1989. From Oct.
1, 1989 to Oct. 1, 1990 a total of 121 cm of precipitation was recorded.
Total tile flow amounted to approximately 19.0 cm with no significant differences
between tillage systems. Movement of water below the tile line was significant
and estimated at 49 cm of water.
No-till had significantly higher average concentration and water flux
averaged concentration of NO3-N in the early spring and fall
periods compared to moldboard, but the reverse was true in the late fall.
The average concentrations in both systems exceeded the drinking water quality
limit of 10 mg/l N03-N. The average concentration was 10.7 mg/l
N03-N in both systems.
Total nitrogen leaching from the 1989 corn crop was estimated at 80 kg
N/ha and 50 kg N/ha in the no-till and conventional till systems respectively.
The increased N leaching in the no-till was attributed to a higher N soil
test in the no-till system and a requirement for less N fertilizer than
the moldboard systems. Both systems had the same fertilizer applied (160
kg N/ha). The amount of N lost by leaching in each replicated plot was significantly
correlated to the difference between the fertilizer N applied and the fertilizer
amount required according to the N soil test.
Detailed transport studies indicated more macropore transport in the
moldboard plough system than the no-till system. However, the average solute
transport velocity was faster in the no-till, which was attributed to increased
occurrence of blocked pore domains.
The no-till system should not result in an increased risk of chemical
contamination of our groundwater resource. If the nitrogen soil test is
used to determine fertilizer requirements then the occurrence of over-application
of N fertilizer should be significantly reduced in all tillage systems.
Surface water runoff from both the no-till and moldboard treatments was
negligible at this site. This was attributed to the very high infiltration
rates of the sand-loam soil. Runoff simulation indicated that increased
water runoff would be expected in the no-till treatment for very large rainfall
events. However, total phosphorus loss would be 2 to 4 times lower than
the moldboard treatment.
Dissolved ortho-phosphorus and nitrate N in runoff water was also very
low in the sandy-loam textured soil. However, runoff simulation on a clay-loam
textured part of the field indicated that ortho-phosphorus in the runoff
was significantly higher in the no-till compared to moldboard treatment.
This, combined with an increased runoff volume from the no-till may be a
problem in heavier textured soils.
(From Technology Transfer Report Summaries - A. Hayes, L. Cruickshank,
The study was conducted to determine the effects of tillage systems on
the quantity and quality of surface runoff and tile drainage water. The
plots were located in Huron County on a long term no- till - moldboard plough
comparison. Tile lines in each of the tillage systems were monitored for
flow quantity, and the concentration of nitrate nitrogen and phosphorus.
Multi-level groundwater samplers were installed to track the movement of
soluble chemicals. Surface runoff was monitored through the use of runoff
collection flumes and rainfall simulation studies were undertaken to characterize
the hydraulic soil properties.
The results of the 2-year study showed that tile flow was no different
between the two tillage systems. No-till had significantly higher average
concentrations of nitrate nitrogen in the early spring and fall compared
to the moldboard but the reverse was true in the late fall (both systems
had concentrations that exceeded drinking water standards). More N leaching
occurred in the no-till than moldboard plough treatment. The increased N
leaching in the no-till was attributed to a higher N soil test in the no-
till system and a requirement for less N fertilizer than the moldboard system
(both systems received the same amount of fertilizer). The amount of N lost
by leaching was correlated to the difference between the fertilizer N applied
and the fertilizer amount required according to the N soil test.
More macropore transport was evident in the moldboard system than the
no-till. However the average solute transport velocity was faster in the
no-till (may be due to the increased occurrence of blocked pores).
Surface runoff was negligible for both treatments (sand-loam soil). Out
of 121 cm of rainfall that fell between Oct./89 and Oct./90, 19 cm left
the site as tile flow and an estimated 49 cm moved below the tile lines
(in both tillage systems). Rainfall simulation trials indicated that increased
water runoff would be expected in the no-till system for very large rainfall
events. However, total phosphorus loss would be 2-4 times lower than the
moldboard system. Runoff simulation on a clay-loam part of the plot indicated
ortho- phosphorus in the runoff was higher in the no-till compared to the
moldboard. With an increased runoff volume from the no-till, this may be
a problem in heavier textured soils.
An excellent study that contains a lot of good information about water
quality and tillage systems for a sandy-loam soil. The higher runoff in
the no-till treatment found in this study contrasts with other American
studies, particularly at Coshocton, and with the results of
SWEEP Report #30 (P. Neave).
SWEEP Report #17 - Effect of Ammonia on Soil
Properties and Relevance to Soil and Water Quality
SWEEP Report #18 - Effects of Management on
Soil Hydraulic Properties
SWEEP Report #23 - Processes Involved in Mobilization
of Phosphorus in Different Farming Systems in Southwestern Ontario: Nutrient
Levels in Plant Tissues and Soils
SWEEP Report #30 - The Response of Soil Microflora
and Fauna to Spring Plowing of Zerotill and Pasture Soils
SWEEP Report #37A - Appendix I-X of SWEEP Report 37
SWEEP Report #45 - Management of Farm Field
Variability. III. Effect of Tillage Systems on Soil and Phosphorus Loss
SWEEP Report #51 - Loss of Nitrogen by Microbial
Denitrification, Nitrification, Surface and Tile Runoff: Relation to Tillage
SWEEP Report #60 - The Effect of Conservation
Tillage Practices on the Losses of Phosphorus and Herbicides in Surface
and Subsurface Drainage Waters
Future Research: ( ) indicates reviewers suggestion for
priority, A - high, C - low.
(A) More work needs to be done on a variety of soils in order to understand
the infiltration/runoff behaviour under different tillage systems.
Thursday, May 19, 2011 03:01:25 PM